铁缺乏对红细胞膜带3蛋白结构相关酶的影响

TX EFFECTS OF IRON DEFICIENCY ON THE ENZYMES BINDING WITH BAND 3 PROTEIN IN ERYTHROCYTE MEMBRANE

方法：测定了１０种红细胞酶。结果：１．缺铁性贫血大鼠红细胞中大多数胞浆酶活力呈代偿性增高，而带３膜绑酶无显著增高表现。２．酶的稳定性在胞浆酶和膜绑酶均明显下降，稳定性测值可作为反映红细胞寿命的一项指标。３．铁缺乏使与ＣＤＢ３结合的ＰＦＫ、Ｇ３ＰＤ的活力与稳定性显著下降；带３蛋白分子降解、含量下降可能是缺铁红细胞膜绑酶病变的直接原因。４．适当的铁剂治疗对于缺铁红细胞酶稳定性的恢复有肯定作用。

The cytoplasmic domain of band 3 protein,the anion transport protein of the red cell,is the high affinity binding site on the red cell membrane for glycolytic enzymes,such as glyceraldehyde3phosphate dehydrogenase,phosphofructokinase and aldolase.The membrane capacity for the three enzymes is coincident with the band 3 protein content.Previous studies have shown that the content of band 3 protein was markedly reduced and the anion transport function of band 3 was strikingly weakned in the red cell of rat with iron deficient anemia.The effects of iron deficiency on the enzymes binding with band 3 protein in membrane and enzymes in cytoplasma of erythrocyte were found that a compensative increase in the activity of the most inspected enzymes in cytoplasma (totally 10) of IDA red cells,which,however, was not seen in the enzymes binding with band 3 in membrane.The stability of enzymes either in cytoplasma or binding with membrane was markedly decreased in IDA red cell especially glyceraldehyde3phosphate dehydrogenase,phosphofructokinase,pyrimidine 5nucleoside,glucose6phosphate dehydrogenase and pyruvate kinase,which indicated that the stability of enzyme in red cell might be associated with the life span of red cell.The reduction in both activity and stability of glyceraldehyde3phosphate dehydrogenase and phosphofructokinase binding with band 3 might result from the reduction of band 3 content due to the cleavage of the protein into band 364kD in IDA red cells.It is suggested that the stability of enzymes in red cell might return to normal by proper iron therapy.